Chemotherapy

A treatment option that kills cancer cells using drugs that have anti-cancer properties.

Purpose of chemotherapy

ChemotherapyChemotherapyTreatment with drugs to kill cancer cells or to render them less active. May be given intravenously or orally depending on the drug and situation. targets cells that divide quickly, such as cancercancerA term used to describe diseases in which abnormal cells continually divide without normal regulation. Cancerous cells may invade surrounding tissues and may spread to other regions of the body via blood and the lymphatic system. cells that grow and multiply without control as well as healthy cells that divide rapidly. MCC is usually initially responsive to chemotherapy, leading to significant shrinkage. However, MCC often quickly gains resistance, and the tumor can start to grow again despite receiving chemotherapy drugs. Adjuvant chemotherapy is chemotherapy that is used to destroy cancer cells that may remain after surgery and/or radiation therapy have cleared the readily detected cancer cells.

Chemotherapy drugs may be given intravenously or orally on certain days of the week over a set number of weeks. For example, a patient may receive chemotherapy Monday, Wednesday and Friday on weeks 1, 4, 7, and 10.

Combination chemotherapy is when two or more drugs are given at the same time as they work better together than alone. MCC has similarities to other neuroendocrineneuroendocrineNeuroendocrine refers to the type of cells that make up Merkel cell carcinoma. "Neuro-" means that these cells have some sensory function related to the nervous system, while "endocrine-" refers to hormonal types of cells. Merkel cells have both such features. carcinomas, such as small cell lung cancer. For this reason, a medical oncologistmedical oncologistA doctor who specializes in the diagnosis and treatment of cancer patients especially using chemotherapy. may use drugs that have shown effectiveness against small cell lung cancer. A combination of etoposideetoposideAn anticancer drug used as a form of chemotherapy. It is often given intravenously or orally in combination with other drugs. Etoposide combined with carboplatin (or cisplatin) is a common therapy for Merkel cell carcinoma in its advanced stages. (VP16) and carboplatincarboplatinA "chemotherapy" drug in the class of DNA alkylating agents that is used to treat some types of cancer. It is closely related to cisplatin but has fewer side effects. (or cis-platin) is one such regimen that will shrink MCC tumors in more than half of cases. A recent study of 62 MCC patients who received chemotherapy to treat distant metastaticmetastaticHaving to do with the spread of cancer from a primary site of origin to distant areas beyond the draining lymph nodes. disease showed that nearly 60% of patients had their tumors shrink initially. On average, however, MCC tumors began to grow again by only 90 days after the chemotherapy was first started (Iyers et al. 2016). When MCC returns after chemotherapy, there are two problems that make controlling it more challenging: the immune system is somewhat suppressed by the chemotherapy and the MCC tumor cells have learned how to evade the effects of chemotherapy drugs. For patients who do not have problems with their immune system (no auto-immune disease and no major immunosuppressive medications), it is typically recommended to first try an immune stimulating therapy (such as an immune checkpoint inhibitor), prior to using chemotherapy.

The following are reasons that adjuvant chemotherapy is not be routinely recommended. In the absence of definitive data, the decision to use chemotherapy should be customized to each situation and should be discussed with a medical team.

Mortality: There is a 4 to 7% acute death rate due to adjuvant chemotherapy in MCC partly due to the fact that these patients are often elderly (Voog 1999; Tai 2000).

Decreased quality of life: This is quite severe in this older population, including fatigue, hair loss, nausea and vomiting.

Resistance to chemotherapy: Merkel cell carcinomaMerkel cell carcinomaA skin cancer composed of cells that look microscopically similar to normal Merkel cells present in the skin. MCC was first described in 1972 and only in the 1990s was the CK20 antibody developed to make it easily identifiable by pathologists. Many doctors and patients are not aware of this cancer because of its recent description and relative rarity (~2,000 cases/year in the US--roughly 30 times less common than melanoma). About 40% of patients treated for MCC will experience a recurrence, making it far more aggressive than most other types of skin cancer, including melanoma. that recurs after chemotherapy is less responsive to later palliativepalliativeRelieving pain or decreasing the severity of a disease. Palliative therapy is usually contrasted with curative therapy (given with intent to cure the patient of cancer). chemotherapy.

Immunity: Chemotherapy suppresses immune function and this is known in general to be very important in preventing and controlling MCC.

Apparent poorer outcomes: In a recent study of 6908 patients captured in the National Cancer Database, there was no benefit (or detriment) of giving adjuvant chemotherapy to patients with high risk disease (MCC that had spread to the nodes).

Who this works for

MCC patients that have not responded to radiation or other treatments and who are not good candidates for immune stimulating therapy. Chemotherapy is generally reserved for later stages, when disease is more wide-spread.

Who this doesn’t work for

Patients who have an intact immune system and no auto-immune disease may benefit from being treated with an immune stimulating therapy prior to trying chemotherapy.

Side effects

Side effects of chemotherapy include, but are not limited to: fatigue, nausea, pain, hair loss, and soreness.

Often used in conjunction with

Chemotherapy is usually used alone as it is often effective, although responses typically only last for a few months.

What to do next

Patients who no longer respond to chemotherapy, may benefit from Pazopanib (Votrient), an oral medication that has been reported to help control metastatic MCC in some cases. Please click here for more details on this drug which was developed for other types of cancers including kidney cancer.

Sandostatin is an agent which can be combined with pazopanib. It works in a different way than pazopanib, and can also sometimes slow or stop the growth of MCC.

FAQs

Do I need chemotherapy?

In general, chemotherapy is reserved for late stages of MCC, when immune therapies are not an option. For disease that is not metastatic, good control can often be achieved with surgery and radiation alone.

Understand the Science

Although Friedrich Merkel believed that the direct connection of these cells to nerves suggested they were ‘touch cells’, it took over 120 years for science to prove this. Studies in which normal Merkel cells were deleted in mice showed that those mice lost normal skin sensation.

Cytotoxic chemotherapy is commonly used to treat advanced Merkel cell carcinoma (MCC). However, its efficacy in distant metastatic MCC patients is unclear, in part because most prior reports aggregated these patients with those receiving adjuvant chemotherapy and combined chemoradiation for whom pro...

The acute and late toxicities of synchronous carboplatin, etoposide, and radiation therapy were prospectively assessed in a group of patients with high-risk Merkel cell carcinoma of the skin.
Patients and Methods:
Forty patients from six different centers throughout Australia were entered into a Pha...